Telephone lines, which are carried by electrical conductors known as tip ring wire pairs, are generally aggregated at a particular point in a building prior to being distributed and connected to various types of telephone equipment, such as, for example, telephones, fax machines, modems etc. As the tip ring pairs generally enter the building as part of a multi-conductor cable, the individual tip ring wire pairs must first be broken out from the cable into individual wire pairs. This is normally accomplished in a junction box known as, for example, a building entrance protector (BEP), or network interface unit (NIU). Within such devices the individual telephone line tip ring pairs are separated from the table, individually connected to a connector block, and made available for further electrical connection and distribution. Usually there is a protector device inserted between the telephone and central office, or network side of the telephone line and the customer equipment or terminal side of the telephone line to protect the telephone and user, or other equipment connected to the telephone line, from hazardous overvoltages induced in the telephone network or in the cables passing between the telephone central office and the building within which the line is terminated.
In a typical arrangement, the telephone lines coming from the network are first wired to a protector field, which is an array of connectors for receiving the protector device, which is in turn hard wired to a first connector block which provides a first test point for testing the telephone line connections between the building and telephone central office. This first terminal block is hard wired to a multi pair connector, most typically a twenty-five pair connector of the RJ21 type, for further connection to an array of customer bridges which are also hard wired and connectorized via a mating RJ21 connector. The use of a customer bridge permits a subscriber to disconnect terminal equipment from a telephone line so that subscriber can isolate troubles on the line as originating in the telephone network, or on the terminal equipment side of the telephone line. An example of such an arrangement is shown in U.S. Pat. No. 5,363,440, dated Nov. 8, 1994, the disclosure of which is incorporated herein by reference. U.S. Pat. No. 5,363,440, depicts a multi-layered network interface unit which results in size economies due to the fact that the customer bridge connector block is hingeably connected to the telephone network protector array field so that rather than placing these two arrays side by side they can be mounted in overlying relationship, resulting in a saving of space.
Additionally, there are known dual sided insulation displacement connector (IDC) blocks for use in such junction boxes and/or distribution fields. These known terminal blocks consist of an IDC type connector on one side of the connector block, and a matching, electrically connected IDC type connector on the other side of the block, and are known as mini-rocker type connectors, such as those sold by A. C. Egerton, LTD.
In some instances it is desirable to have exit apertures or feed through holes to pass a tip ring pair of wires to multiple different connectors. This would have the advantage of enabling customers to branch wires between terminals. However, permanent feed through holes are disadvantageous in two ways. First, the wire retention regions of IDC type connectors are optionally filled with a gel to ensure proper electrical connections and to prevent rusting of terminal points. Since the gel lacks viscosity when first injected into the wire passages and would easily flow out of the feed through hole, connectors having permanent feed through holes cannot be readily gel filled. Second, in certain applications, customers may not wish to branch wires between terminals. In such applications, the customer must trim the wires flush with the connector surface so that it does not protrude past the feed through hole. The trimmed wires may then land between terminals causing electrical shorts. In addition, the wire trimming procedure results in additional labor, time, and thus additional cost.
Although present connectors without feed through holes eliminate the aforementioned problems with permanent feed through holes, such connectors are disadvantageous because they offer the customer no flexibility to branch wires between terminals.